Scientific literature suggests that supplementation of infant formula with the long chain polyunsaturated fatty acids (LC-PUFA) docosahexaenoic acid (DHA, omega 3) and arachidonic acid (ARA, omega 6) may have many health benefits for the infant. Indeed it has been demonstrated that in pre-term infants receiving DHA and ARA either from breast milk or infant formula containing these LC-PUFA demonstrate improved cognitive abilities, visual acuity and motor skills when compared with unsupplemented pre-term infants. The picture for term infants is less clear. Some studies have been published showing similar benefits of supplementation to those demonstrated with pre-term infants but other studies have found no effect of supplementation.
It has been suggested that these conflicting results with term infants could be due to the influence of maternal LC-PUFA status. DHA in particular is accumulated preferentially to other fatty acids by the foetus in the last trimester of pregnancy. In premature birth, this period does not last the full three months and it may be expected that the response of the pre-term infant to supplementation with DHA would be marked. A term infant, however, would have the benefit of maternal supply during the last three months of gestation and, assuming that supply to be adequate, could be expected to have adequate or near adequate DHA status at birth.
However, in the developed world at least, there are increasing concerns over the physiological effects of a diet rich in saturated fats and favouring the precursors of omega 6 LC-PUFA such as ARA at the expense of the precursors of omega 3 LC-PUFA such as DHA on the physiological omega 6:omega 3 ratio in general. In particular, there are concerns that pregnant women eating a normal Western diet may not be able to supply sufficient omega 3 precursors to meet the developing foetus's need to synthesise DHA. For this reason it has been proposed for example in WO 2003/017945 to develop a range of supplements for pregnant women containing DHA with ARA and various vitamins and minerals. It is claimed that taking such supplements could benefit the health of both mother and baby. Examples of possible benefits to the unborn baby are stated to include optimised growth and development of the nervous system and improved foetal weight gain.
The prevalence of obesity in adults, adolescents and children has increased rapidly and research to identify approaches to prevent overweight and obesity in childhood is considered to be of major public health importance. Overweight and obesity in childhood is a relatively recent phenomenon that already affects over 15 million children under age 5 across the world. Almost 30% of adolescents and children in the US and between 10 and 30% of children in Europe may be classified as overweight or obese. It has been suggested that rapid growth during the first four months of life may be associated with the development of overweight or obesity later in life and that the rate of weight gain in the first few weeks of life may be particularly important.
Recently, attention has focused on the possible role of LC-PUFA in the development and treatment of overweight and obesity. For example, WO 2004/012727 discloses a method for decreasing the appetite of a mammal comprising enterally administering an omega 3 LC-PUFA to the mammal. Ruzickova J. et al. (Lipids. 2004 December; 39(12):1177-85) document augmentation of the antiadipogenic effect of EPA/DHA during development of obesity and suggest that EPA/DHA could reduce accumulation of body fat by limiting both hypertrophy and hyperplasia of fat cells.
However, Lauritzen L. et al. (Maternal fish oil supplementation in lactation and growth during the first 2.5 years of life. Pediatr Res. 2005 August; 58(2):235-42) performed a randomized trial on mothers after delivery. The women were randomly assigned to take a supplement of fish oil (rich in omega 3 LC-PUFA such as DHA) or olive oil. The supplement was taken during 0 to 4 months of lactation. 122 children were studied of whom 70 were followed up until 30 months. The BMI of the children was measured at birth and at 2, 4, 9 and 30 months of age. The results showed that the BMI of infants in the fish oil group was higher than the BMI of infants in the olive oil group from the age of 9 months on.
There remains a need to provide alternative methods to address the risk of overweight and obesity, particularly during childhood.